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2007

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Articles 1081 - 1110 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Search For Stopped Gluinos From Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration Sep 2007

Search For Stopped Gluinos From Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles’ decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g̃), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb-1 of pp̅ collisions at √s = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron …


Transients Of The Electromagnetically-Induced-Transparency-Enhanced Refractive Kerr Nonlinearity, John C. Howell, M. V. Pack, R. M. Camacho Sep 2007

Transients Of The Electromagnetically-Induced-Transparency-Enhanced Refractive Kerr Nonlinearity, John C. Howell, M. V. Pack, R. M. Camacho

Mathematics, Physics, and Computer Science Faculty Articles and Research

We report observations of the dynamics of electromagnetically induced transparency (EIT) in a Λ system when the ground states are Stark shifted. Interactions of this type exhibit large optical nonlinearities called Kerr nonlinearities, and have numerous applications. The EIT Kerr nonlinearity is relatively slow, which is a limiting factor that may make many potential applications impossible. Using rubidium atoms, we observe the dynamics of the EIT Kerr nonlinearity using a Mach-Zehnder interferometer to measure phase modulation of the EIT fields resulting from a pulsed signal beam Stark shifting the ground state energy levels. The rise times and transients agree well …


National Wildlife Research Center: Research Update Summer 2007 Sep 2007

National Wildlife Research Center: Research Update Summer 2007

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife Services: Vision and Strategic Goals
Spotlight on NWRC Rice Research
Blackbird Damage
History of Rice Research
NWRC Realigns Research Programs
WS Partners with Chinese Scientists to Study Role of Wildlife as Carriers of Avian Influenza
Rodent Control Collaboration at Army Training Area
NWRC Field Station Assists University of Hawaii Anthropology Department
Developing Methods & Providing Wildlife Services
EPA Registers Oral Contraceptive for Pigeons
New DRC-1339 “Take” Models Available for Use
Oregon and Washington Register a New Forest Pest Management Tool
Researchers Present Method for Permitted Take of Migratory Birds
New HPCL Analytical Method Developed for Warfarin
WS Begins Efforts …


Who Will Put America Back Together Again?, David J. Keeling Sep 2007

Who Will Put America Back Together Again?, David J. Keeling

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


The Tropical Forest And Fire Emissions Experiment: Trace Gases Emitted By Smoldering Logs And Dung From Deforestation And Pasture Fires In Brazil, Ted J. Christian, Robert J. Yokelson, João A. Carvalho, David W.T. Griffith, Ernesto C. Alvarado, José Carlos Santos, Turibio Gomes Soares Neto, Carlos A.Gurgel Veras, Wei Min Hao Sep 2007

The Tropical Forest And Fire Emissions Experiment: Trace Gases Emitted By Smoldering Logs And Dung From Deforestation And Pasture Fires In Brazil, Ted J. Christian, Robert J. Yokelson, João A. Carvalho, David W.T. Griffith, Ernesto C. Alvarado, José Carlos Santos, Turibio Gomes Soares Neto, Carlos A.Gurgel Veras, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

Earlier work showed that Amazonian biomass burning produces both lofted and initially unlofted emissions in large amounts. A mobile, Fourier transform infrared spectrometer (FTIR) measured the unlofted emissions of 17 trace gases from residual smoldering combustion (RSC) of logs as part of the Tropical Forest and Fire Emissions Experiment (TROFFEE) during the 2004 Amazonian dry season. The RSC emissions were highly variable and the few earlier RSC measurements lay near the high end of combustion efficiency observed in this study. Fuel consumption by RSC was ∼5% of total for a planned deforestation fire. Much regional RSC probably occurs in the …


Limitations And Extensions Of The Wolf-Phc Algorithm, Philip R. Cook Sep 2007

Limitations And Extensions Of The Wolf-Phc Algorithm, Philip R. Cook

Theses and Dissertations

Policy Hill Climbing (PHC) is a reinforcement learning algorithm that extends Q-learning to learn probabilistic policies for multi-agent games. WoLF-PHC extends PHC with the "win or learn fast" principle. A proof that PHC will diverge in self-play when playing Shapley's game is given, and WoLF-PHC is shown empirically to diverge as well. Various WoLF-PHC based modifications were created, evaluated, and compared in an attempt to obtain convergence to the single shot Nash equilibrium when playing Shapley's game in self-play without using more information than WoLF-PHC uses. Partial Commitment WoLF-PHC (PCWoLF-PHC), which performs best on Shapley's game, is tested on other …


Using A Mini-Uav To Support Wilderness Search And Rescue: Practices For Human-Robot Teaming, Julie A. Adams, Brian G. Buss, Joseph L. Cooper, Michael A. Goodrich, Curtis Humphrey, Ron Zeeman Sep 2007

Using A Mini-Uav To Support Wilderness Search And Rescue: Practices For Human-Robot Teaming, Julie A. Adams, Brian G. Buss, Joseph L. Cooper, Michael A. Goodrich, Curtis Humphrey, Ron Zeeman

Faculty Publications

Wilderness Search and Rescue can benefit from aerial imagery of the search area. Mini Unmanned Aerial Vehicles can potentially provide such imagery, provided that the autonomy, search algorithms, and operator control unit are designed to support coordinated human-robot search teams. Using results from formal analyses of the WiSAR problem domain, we summarize and discuss information flow requirements for WiSAR with an eye toward the efficient use of mUAVs to support search. We then identify and discuss three different operational paradigms for performing field searches, and identify influences that affect which human-robot team paradigm is best. Since the likely location of …


Shallow Slab Fluid Release Across And Along The Mariana Arc-Basin System: Insights From Geochemistry Of Serpentinized Peridotites From The Mariana Fore Arc, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Patricia Fryer Sep 2007

Shallow Slab Fluid Release Across And Along The Mariana Arc-Basin System: Insights From Geochemistry Of Serpentinized Peridotites From The Mariana Fore Arc, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Patricia Fryer

Geology Faculty Publications

Shallow slab devolatilization is not only witnessed through fluid expulsion at accretionary prisms, but is also evidenced by active serpentinite seamounts in the shallow fore-arc region of the Mariana convergent margin. Ocean Drilling Program (ODP) Leg 195 recovered serpentinized peridotites that present a unique opportunity to study the products of shallow level exchanges between the upper mantle and slab-derived fluids. Similar to samples recovered during ODP Leg 125, the protoliths of these fore-arc serpentinized peridotites are mantle harzburgites that have suffered large volume melt extraction (up to 25%) prior to interactions with fluids released from the downgoing Pacific Plate. Samples …


Search For Gravitational Wave Radiation Associated With The Pulsating Tail Of The Sgr 1806-20 Hyperflare Of 27 December 2004 Using Ligo, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales Sep 2007

Search For Gravitational Wave Radiation Associated With The Pulsating Tail Of The Sgr 1806-20 Hyperflare Of 27 December 2004 Using Ligo, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales

Faculty Publications

We have searched for gravitational waves (GWs) associated with the SGR 1806-20 hyperflare of 27 December 2004. This event, originating from a Galactic neutron star, displayed exceptional energetics. Recent investigations of the x-ray light curve's pulsating tail revealed the presence of quasiperiodic oscillations (QPOs) in the 30-2000 Hz frequency range, most of which coincides with the bandwidth of the LIGO detectors. These QPOs, with well-characterized frequencies, can plausibly be attributed to seismic modes of the neutron star which could emit GWs. Our search targeted potential quasimonochromatic GWs lasting for tens of seconds and emitted at the QPO frequencies. We have …


Contact Metamorphism In The Malashan Dome, North Himalayan Gneiss Domes, Southern Tibet: An Example Of Shallow Extensional Tectonics In The Tethys Himalaya, Tetsuo Kawakami, Mutsuki Aoya, Simon Wallis, Jeffrey Lee, Kentaro Terada, Yu Wang, Matt Heizler Sep 2007

Contact Metamorphism In The Malashan Dome, North Himalayan Gneiss Domes, Southern Tibet: An Example Of Shallow Extensional Tectonics In The Tethys Himalaya, Tetsuo Kawakami, Mutsuki Aoya, Simon Wallis, Jeffrey Lee, Kentaro Terada, Yu Wang, Matt Heizler

All Faculty Scholarship for the College of the Sciences

Combined petrographic, structural and geochronological study of the Malashan dome, one of the North Himalayan gneiss domes, reveals that it is cored by a Miocene granite, the Malashan granite, that intruded into the Jurassic sedimentary rocks of Tethys Himalaya. Two other granites in the area are referred to as the Paiku and Cuobu granites. New zircon SHRIMP U-Pb and muscovite and biotite 40Ar-39Ar dating show that the Paiku granite was emplaced during 22.2–16.2 Ma (average 19.3 ± 3.9 Ma) and cooled rapidly to 350–400 °C at around 15.9 Ma. Whole-rock granite chemistry suggests the original granitic magma …


Location-Based Services In Emergency Management- From Government To Citizens: Global Case Studies, A. Aloudat, Katina Michael, Jun Yan Sep 2007

Location-Based Services In Emergency Management- From Government To Citizens: Global Case Studies, A. Aloudat, Katina Michael, Jun Yan

Faculty of Informatics - Papers (Archive)

In emergencies governments have long utilised broadcasting media like radio and television to disseminate up-to-date real-time information to citizens. In the same context, however, some other technologies like mobile location-based services have not been utilised to full extent or potential. The value of such services could be foreseen in the case of critical situations where the coordination of emergency management procedures with location-awareness activities is paramount. This paper tracks the introduction of location-aware services in the realm of emergency management. It investigates case studies where text messaging has been exploited to deliver safety information and early warnings to users based …


The Electronic Structure Change With Gd Doping Of Hfo2 On Silicon, Yaroslav B. Losovyj, Ihor Ketsman, Andrei Sokolov, Kirill D. Belashchenko, Peter A. Dowben, Jinke Tang, Zhenjun Wang Sep 2007

The Electronic Structure Change With Gd Doping Of Hfo2 On Silicon, Yaroslav B. Losovyj, Ihor Ketsman, Andrei Sokolov, Kirill D. Belashchenko, Peter A. Dowben, Jinke Tang, Zhenjun Wang

Peter Dowben Publications

Gd-doped HfO2 films deposited on silicon substrates undergo a crystallographic change from monoclinic to fluorite (cubic) phase with increasing Gd concentrations. The crystallographic phase change is accompanied by a small increase in the valence bandwidth and in the apparent band offset in the surface region. Electrical measurements show pronounced rectification properties for lightly doped Gd:HfO2 films on p-Si and for heavily-doped Gd:HfO2 films on n-Si, suggesting a crossover from n-type to p -type behavior with increasing doping level.


Semilinear Spdes As Dynamical Systems (Mittag-Leffler Institute Seminar), Salah-Eldin A. Mohammed Sep 2007

Semilinear Spdes As Dynamical Systems (Mittag-Leffler Institute Seminar), Salah-Eldin A. Mohammed

Miscellaneous (presentations, translations, interviews, etc)

No abstract provided.


A Utile Function Optimizer, James Carroll, Christopher K. Monson, Kevin Seppi Sep 2007

A Utile Function Optimizer, James Carroll, Christopher K. Monson, Kevin Seppi

Faculty Publications

We recast the problem of unconstrained continuous evolutionary optimization as inference in a fixed graphical model. This approach allows us to address several pervasive issues in optimization, including the traditionally difficult problem of selecting an algorithm that is most appropriate for a given task. This is accomplished by placing a prior distribution over the expected class of functions, then employing inference and intuitively defined utilities and costs to transform the evolutionary optimization problem into one of active sampling. This allows us to pose an approach to optimization that is optimal for each expressly stated function class. The resulting solution methodology …


Parallel Pso Using Mapreduce, Andrew Mcnabb, Christopher K. Monson, Kevin Seppi Sep 2007

Parallel Pso Using Mapreduce, Andrew Mcnabb, Christopher K. Monson, Kevin Seppi

Faculty Publications

In optimization problems involving large amounts of data, such as web content, commercial transaction information, or bioinformatics data, individual function evaluations may take minutes or even hours. Particle Swarm Optimization (PSO) must be parallelized for such functions. However, large-scale parallel programs must communicate efficiently, balance work across all processors, and address problems such as failed nodes. We present MapReduce Particle Swarm Optimization (MRPSO), a PSO implementation based on the MapReduce parallel programming model. We describe MapReduce and show how PSO can be naturally expressed in this model, without explicitly addressing any of the details of parallelization. We present a benchmark …


Shape Invariance And The Exactness Of Quantum Hamilton-Jacobi Formalism, Charles Cherqui, Yevgeny Binder, Asim Gangopadhyaya Sep 2007

Shape Invariance And The Exactness Of Quantum Hamilton-Jacobi Formalism, Charles Cherqui, Yevgeny Binder, Asim Gangopadhyaya

Physics: Faculty Publications and Other Works

Quantum Hamilton-Jacobi Theory and supersymmetric quantum mechanics (SUSYQM) are two parallel methods to determine the spectra of a quantum mechanical systems without solving the Schr ̈odinger equation. It was recently shown that the shape invariance, which is an integrability condition in SUSYQM formalism, can be utilized to develop an iterative algorithm to determine the quantum momentum functions. In this paper, we show that shape invariance also suffices to determine the eigenvalues in Quantum Hamilton-Jacobi Theory.


Yasir: A Low-Latency, High-Integrity Security Retrofit For Legacy Scada Systems, Patrick P. Tsang, Sean W. Smith Sep 2007

Yasir: A Low-Latency, High-Integrity Security Retrofit For Legacy Scada Systems, Patrick P. Tsang, Sean W. Smith

Computer Science Technical Reports

We construct a bump-in-the-wire (BITW) solution that retrofits security into time-critical communications over bandwidth-limited serial links between devices in Supervisory Control And Data Acquisition (SCADA) systems. Previous BITW solutions fail to provide the necessary security within timing constraints; the previous solution that does provide the necessary security is not BITW. At a comparable hardware cost, our BITW solution provides sufficient security, and yet incurs minimal end-to-end communication latency. A microcontroller prototype of our solution is under development.


Enhancement Of Nd: Yag Libs Emission Of A Remote Target Using A Simultaneous Co/Sub 2/ Laser Pulse, Dennis K. Killinger, Susan D. Allen, Robert D. Waterbury, Chris Stefano, Edwin L. Dottery Sep 2007

Enhancement Of Nd: Yag Libs Emission Of A Remote Target Using A Simultaneous Co/Sub 2/ Laser Pulse, Dennis K. Killinger, Susan D. Allen, Robert D. Waterbury, Chris Stefano, Edwin L. Dottery

Publications

For the first time to the best of our knowledge, a simultaneous 10.6 μm CO2 laser pulse has been used to enhance the Laser Induced Breakdown Spectroscopy (LIBS) emission from a 1.064 μm Nd:YAG laser induced plasma on a hard target. The enhancement factor was on the order of 25 to 300 times, depending upon the emission lines observed. For an alumina ceramic substrate the Al emission lines at 308 nm and Fe impurity line at 278 nm showed an increase of 60x and 119x, respectively. The output energy of the Nd:YAG laser was 50 mJ/pulse focused to a 1 …


Blueprint For Iteratively Hardening Power Grids Employing Unified Power Flow Controllers, William M. Siever, Ann K. Miller, Daniel R. Tauritz Sep 2007

Blueprint For Iteratively Hardening Power Grids Employing Unified Power Flow Controllers, William M. Siever, Ann K. Miller, Daniel R. Tauritz

Electrical and Computer Engineering Faculty Research & Creative Works

A stable electricity supply is vital for modern society. However, many parts of our power transmission grid are operating near their operational limits. Such stressed systems are vulnerable to cascading failures, where a few small faults can induce a cascade of failures potentially leading to a major blackout The unified power flow controller (UPFC), the most powerful highspeed, semi-conductor based power flow device, can be used as a theoretical model to study how these devices can be used to improve power grid resilience. The blueprint presented here can be used to iteratively identify critical weaknesses in power grids and to …


Using Lax Scintillator In A New Low-Background Compton Telescope, James M. Ryan, Peter F. Bloser, John R. Macri, Mark L. Mcconnell Sep 2007

Using Lax Scintillator In A New Low-Background Compton Telescope, James M. Ryan, Peter F. Bloser, John R. Macri, Mark L. Mcconnell

Space Science Center

The ability of Compton telescopes to perform imaging and spectroscopy in space depends directly on the speed and energy resolution of the calorimeter detectors in the telescope. The calorimeter detectors flown on space-borne or balloon-borne Compton telescopes have included NaI(Tl), CsI(Na), HPGe and liquid organic scintillator. By employing LaX scintillators for the calorimeter, one can take advantage of the unique speed and resolving power of the material to improve the instrument sensitivity and simultaneously enhance its spectroscopic performance and thus its imaging performance. We present a concept for a space-borne Compton telescope that employs LaX as a calorimeter and estimate …


Gauge-Gravity Duality -- Super Yang Mills Quantum Mechanics, Simon Catterall, Toby Wiseman Sep 2007

Gauge-Gravity Duality -- Super Yang Mills Quantum Mechanics, Simon Catterall, Toby Wiseman

Physics - All Scholarship

We describe the conjectured holographic duality between Yang-Mills quantum mechanics and type IIa string theory. This duality allows us to use lattice Monte Carlo simulations to probe the physics of the gravitational theory - for example, at low energies it provides a computation of black hole entropy in terms of a sum over microstates of the dual gauge theory. Numerical results are presented of the 4 supercharge theory at finite temperature.


Gopherus Polyphemus (Gopher Tortoise) Mortality, Richard M. Engeman, Henry T. Smith, Gregory S. Kaufman Sep 2007

Gopherus Polyphemus (Gopher Tortoise) Mortality, Richard M. Engeman, Henry T. Smith, Gregory S. Kaufman

United States Department of Agriculture Wildlife Services: Staff Publications

Gopherus polyphemus has declined precipitously in range and numbers in Florida and recently was state-listed as a "threatened" species under the Florida Wildlife Code (Chap. 39, Florida Administrative Code). At ca. 1000 h on 27 July 2006, GK observed a 23 cm carapace length male G. polyphemus between the North- South railroad tracks on the eastern boundary of Savannas Preserve State Park (SPSP) in St. Lucie County, Florida (Fig. 1). The tortoise seemed uninjured, but was deceased. Eastern Box Turtles (Terrapene carolina) were recently shown to have great difficulty escaping railroad tracks, with overheating to critical levels likely …


Lighting And Optical Tools For Image Forensics, Micah Kimo Johnson Sep 2007

Lighting And Optical Tools For Image Forensics, Micah Kimo Johnson

Dartmouth College Ph.D Dissertations

We present new forensic tools that are capable of detecting traces of tampering in digital images without the use of watermarks or specialized hardware. These tools operate under the assumption that images contain natural properties from a variety of sources, including the world, the lens, and the sensor. These properties may be disturbed by digital tampering and by measuring them we can expose the forgery. In this context, we present the following forensic tools: (1) illuminant direction, (2) specularity, (3) lighting environment, and (4) chromatic aberration. The common theme of these tools is that they exploit lighting or optical properties …


A Determination Of The Spin-Orbit Alignment Of The Anomalously Dense Planet Orbiting Hd 149026, Aaron S. Wolf, Gregory Laughlin, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt Sep 2007

A Determination Of The Spin-Orbit Alignment Of The Anomalously Dense Planet Orbiting Hd 149026, Aaron S. Wolf, Gregory Laughlin, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt

Information Systems and Engineering Management Research Publications

We report 35 radial velocity measurements of HD 149026 taken with the Keck Telescope. Of these measurements, 15 were made during the transit of the companion planet HD 149026b, which occurred on 2005 June 25. These velocities provide a high-cadence observation of the Rossiter-McLaughlin effect, the shifting of photospheric line profiles that occurs when a planet occults a portion of the rotating stellar surface. We combine these radial velocities with previously published radial velocity and photometric data sets and derive a composite best-fit model for the star-planet system. This model confirms and improves previously published orbital parameters, including the remarkably …


U.S. Law Of The Sea Cruise To Map The Foot Of The Slope And 2500-M Isobath Of The U.S. Arctic Ocean Margin. Cruise Report For 2007, Larry A. Mayer, Andy Armstrong Sep 2007

U.S. Law Of The Sea Cruise To Map The Foot Of The Slope And 2500-M Isobath Of The U.S. Arctic Ocean Margin. Cruise Report For 2007, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

USCGC Icebreaker Healy (WAGB-20) U.S. Law of the Sea cruise to map the foot of the slope and 2500-m isobath of the US Arctic Ocean margin

CRUISES HE-0703

August 17 to September 15, 2007

Barrow, AK to Barrow, AK


Soil Carbon And Tree Litter Dynamics In A Red Cedar–Scotch Pine Shelterbelt, Thomas J. Sauer, Cynthia A. Cambardella, James R. Brandle Sep 2007

Soil Carbon And Tree Litter Dynamics In A Red Cedar–Scotch Pine Shelterbelt, Thomas J. Sauer, Cynthia A. Cambardella, James R. Brandle

School of Natural Resources: Faculty Publications

Carbon sequestration in the woody biomass of shelterbelts has been investigated but there have been no measurements of the C stocks in soil and tree litter under this agroforestry practice. The objective of this study was to quantify C stored in surface soil layers and tree litter within and adjacent to a 35-year-old shelterbelt in eastern Nebraska, USA. The 2-row shelterbelt was composed of eastern red cedar (Juniperus virginiana) and scotch pine (Pinus sylvestris). A sampling grid was established across a section of the shelterbelt on Tomek silt loam (fine, smectitic, mesic Pachic Argiudolls). Four soil …


The Tropical Forest And Fire Emissions Experiment: Emission, Chemistry, And Transport Of Biogenic Volatile Organic Compounds In The Lower Atmosphere Over Amazonia, Thomas Karl, Alex Guenther, Robert J. Yokelson, Jim Greenberg, Mark Potosnak, Donald R. Blake, Paulo Artaxo Sep 2007

The Tropical Forest And Fire Emissions Experiment: Emission, Chemistry, And Transport Of Biogenic Volatile Organic Compounds In The Lower Atmosphere Over Amazonia, Thomas Karl, Alex Guenther, Robert J. Yokelson, Jim Greenberg, Mark Potosnak, Donald R. Blake, Paulo Artaxo

Chemistry and Biochemistry Faculty Publications

Airborne and ground-based mixing ratio and flux measurements using eddy covariance (EC) and for the first time the mixed layer gradient (MLG) and mixed layer variance (MLV) techniques are used to assess the impact of isoprene and monoterpene emissions on atmospheric chemistry in the Amazon basin. Average noon isoprene (7.8 +/- 2.3 mg/m(2)/h) and monoterpene fluxes (1.2 +/- 0.5 mg/m(2)/h)compared well between ground and airborne measurements and are higher than fluxes estimated in this region during other seasons. The biogenic emission model, Model of Emissions of Gases and Aerosols from Nature (MEGAN), estimates fluxes that are within the model and …


Investigation Of The Gas Phase Reactivity Of The 1-Adamantyl Radical Using A Distonic Radical Anion Approach, D. G. Harman, Stephen J. Blanksby Sep 2007

Investigation Of The Gas Phase Reactivity Of The 1-Adamantyl Radical Using A Distonic Radical Anion Approach, D. G. Harman, Stephen J. Blanksby

Faculty of Science - Papers (Archive)

The gas phase reactions of the bridgehead 3-carboxylato-1-adamantyl radical anion were observed with a series of neutral reagents using a modified electrospray ionisation linear ion trap mass spectrometer. This distonic radical anion was observed to undergo processes suggestive of radical reactivity including radical-radical combination reactions, substitution reactions and addition to carbon-carbon double bonds. The rate constants for reactions of the 3-carboxylato-1-adamantyl radical anion with the following reagents were measured (in units 10 12 cm3 molecule 1 s 1): 18O2 (85±4), NO (38.4±0.4), I2 (50±50), Br2 (8±2), CH3SSCH3 (12±2), styrene (1.20±0.03), CHCl3 (H abstraction 0.41±0.06, Cl abstraction 0.65±0.1), CDCl3 (D abstraction …


The First Frontier: High Altitude Ballooning And Access To Near Space, Shane L. Larson Sep 2007

The First Frontier: High Altitude Ballooning And Access To Near Space, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Reduction Of Esters To Ethers Utilizing The Powerful Lewis Acid Bf2otf·Oet2, Brian Pagenkopf, Nicholas A. Morra Sep 2007

Reduction Of Esters To Ethers Utilizing The Powerful Lewis Acid Bf2otf·Oet2, Brian Pagenkopf, Nicholas A. Morra

Chemistry Publications

No abstract provided.